Assistant Professor of Applied Statistics

Daphna Harel is an applied statistician who studies issues of measurement and modeling in the applied health sciences. Her research focuses on modeling challenges for data arising from self-reported questionnaires and crowdsourcing, and requiring the use of multilevel models. Her methodological work focuses on the creation of theoretically justified guidelines for statistical analysis and issues of model misspecification in polytomous Item Response Theory, and the shortening of patient reported outcome measures. Harel received her PhD from the Department of Mathematics and Statistics at McGill University.

Item Response Theory: Dr. Harel works on developing principled approaches to measurement problems in the social sciences. Harel advocates for the use of statistics and procedures that minimize the impact of misspecification between the data-generating model and the model used for analysis. Her work includes the development of a weighted summed score for ranking respondents based on responses to polytomous questionnaires and the impact of collapsing score categories.

Measurement in Systemic Sclerosis: Dr. Harel works on measurement of latent traits in chronically ill populations. Through her work with the Canadian Scleroderma Research Group and the Scleroderma Patient-centered Intervention Network, Harel has improved the quality of instruments used to measure health-related quality-of-life in patients with Systemic Sclerosis. Her most recent project focuses on the shortening of patient reported outcome measures through data-driven approaches.

Modeling in Health Sciences: Dr. Harel collaborates with experts in the communicative sciences and disorders, as well as physical therapy, to transform the way researchers analyze their data. These projects usually involve the use of multilevel, or mixed-effects, models to best capture data arising from repeated measurement designs.

SurveyDesign: Dr. Harel is an expert in survey design, and the modeling of survey data. Her recent work includes the development of a survey to measure hard-to-operationalize concepts in Nairobi and Karachi.